Silybum Marianum Royalty-Free Stock Image

Milk thistles can grow to be 30 to 200 cm 12 to 79 in tall, and have an overall conical shape. The approximate maximum base diameter is 160 cm 63 in. The stem is grooved and more or less cottony. The largest specimens have hollow stems.nnThe leaves are oblong to lanceolate. They are either lobate or pinnate, with spiny edges. They are hairless, shiny green, with milk-white veins.nnThe flower heads are 4 to 12 cm long and wide, of red-purple colour. They flower from June to August in the North or December to February in the Southern Hemisphere summer through autumn.nnThe bracts are hairless, with triangular, spine-edged appendages, tipped with a stout yellow spine.nnThe achenes are black, with a simple long white pappus, surrounded by a yellow basal ring